Fluid pressure brake



Jan. 26, 1.932. T. H. THOMAS 1,842,484

FLUID PRESSURE BRAKE Original Filed Nov. 16, 1929 63 7 INVENTOR THOMASH.THOMA$ DECEASED ATTOR EY Patented JanQZ G, 1932" THOMAS, EXECU'IRIX;or nnenwoon,

nnenwoon, rmvnsynvnnm, Y MAIBlLiE M. PENNSYLVANIA, ASSIGNOR TO THE WEST;

I THOMAS i1. moms,- emerges, LATE or rue rouse ra BRAKE'OOMIEANY, orw'rmvrennnve; PENNSYLVANIA, A CORPORA- ron OF PENN$YIiVANIA FLUIDrREssURE BaAxE g i wApplication filed nb eer 6,1929, Se

invention relates to fluid 1 pressure brakes, andmore particularly toabrake equipment having means for-regulating the .rate of build upofbrake cylinder pressure during an emergency application of the l a ibrakes.

It has heretofore proposed to provide a fluid pressurebrake equipment inwhich l an emergency application ofithe brakes,

an initialinshot of fluid under pressure is supplied to the brakecylinder, which is suf: ficient to move the brake cylinder pistonoutf'an d bring the brake shoes into engages a ment vvith the' car"wheels. This is followed a 15 i by supplying fluid under pressureto thebrakejcylinderat a slow rate for a time in-V terval sulficient to?permit the brakes to be radually; applied throughout the .train.inally,"after the brake cylinder pressure has 11 beengradually built upto apre deten mined degreg'ja final; inshoti of fluid under i pressureis supplied to the brakejcylinder,

inordertto provide the desired high degree i brake Cylinder pressureinan emergency application otthe brakes; ,An equipment voi Qtheabovecharacteris disclosedinthe prior patent-ofO. Ci Farmer, jNo.1,585,77hissued May,25,1926.; a

I 5 O eobject of the invention is to provide an improved and simplifiedfluid pressure brake equipment ofthe above character. r I

Other objects and advantages will appear .in a the 1 following i more{detailed description of the invention. i i 1 In tl e accompanyingdrawing the single t figureis a. diagrammatic View, partly .in sectionof a fluid pressurebrake equipment embodyin g my invention. a a

As shown in the drawingyithe"equipment maycomprise 1a. triple valvedevice 1, an emergency valve device 2, aninshotfvalve device 3, a delayvalve device l, a brake-cylinder 5, anda; brake pipe 7Thertriplevalvefdevicel; may comprise a casinghaving a piston chamber.8, connected throughdpassage 9 with brake pipe 7 and containing piston 10, and a 'valve chamber 11,]connectedzthroughr passage 12 withmanauxiliary"reservoiri 13, and containing a X 7 main slide valve 14, and agraduatlngsllde rial No. 407,623, nenewea my n, 1931..

valve 15,:adapted tobe operatedby piston 10.

pipe; 7 andicontaining piston 17 and having a valve chamber 18,connectedthrough pas sage l9with a quick actionchamber 20 and containing a mainslide valve 21, and a graduating slide valve 22, adapted tobe operated 5,1 a i 7'00 Theinshot valve device 3 comprises a valve chamber 24 at oneside i by piston 17 Ipiston 23 having the Ihe emergencyvalvedevice 2 maycom 1 prise .a casing having a pistonchamber 16,- ccnnected through.passage 57 with brake connected to a passage25 leading to the seat:

of slide valve QIuAThe valve piston 23 is adapted inits down position toengage a seat rib26 and isurged tothis position bya coil spring 27. Thevalver piston 23 carries a ste1n28, to which is secured a piston valve29, i

and the chamber 30vintermediatethe piston valve 29. andthevalve piston23 is connected, throughpassages 131 and 32 with leadingto brakecylinder 5.

pipe 38,

The delaytvalve devicel comprises a valve piston having a valve seat 92adapted to envalve piston is urgedto its up position by acoilspring35.

The chamber 36 at the lower face of the valve piston 4 is connected to apassage 37,

emergency reservoir 38 is connected through face ofthe valve piston Landsaid chamberis also connected to a passage 41, leading to the seat ofslide valve 21. r

Fluid githen I flows from piston chamber 1 throughpassageu58,pastchecklvalve 59, and through-passage 60 to valve chamber11, and

I from valve chamber 115 through passage 12 to the auxiliary reservoir13, thus charging" the auxiliaryhreservoir and thevalvle l chamberll. "w

leading to the seat ofislideyvalvefll. An

passage'39 with chambertdatthe upper "Fluid; alsofiows-from passage 58,past check valvefil t0 passage 62,- which is con l l In operation, whenthe brake pipe 7is charged-with fluid under pressure in the usual.:"manner,' fluid :flows from the brake pipe 1 through passage 9 topiston chamber 8 of the triplevalve device 1 and shifts piston 10 torelease position, as shown-injthe drawing.

gage a seatribfiin its up position andsaid 7 nected through pipe 63 andpassage 39 with the emergency reservoir 38, sothat the emergencyreservoir is charged with fluid under ressure. Fluid under presure flowsfrom the brake pipe 7, throughpassage 57 to piston chamber 16 of theemergency valve device 2 and shifts the piston 17 to release position,as shown in the drawing.

In release position, fluid flows from piston chamber 16, through passage64, past check valve'65, to passage 66 and then to'valve chamber 18, andfrom valve vhamber 18, through passage 19 to quick action chamber 20, sothat said chambers are charged with fluid at brake pipe pressure. 7 a IIn the release position of the triple valve device 1, the brake cylinder5 is connected to the atmosphere, through pipe 33, passage 69, cavity 7Oin slide valve 14 and atmospheric exhaust port 68.

With the emergency valve device 2 in repassage 41, cavity 71 in slidevalve 21, and

passage 25. Chamber 36 at the lower face of the delay valve piston 4 is.also charged with fluid at emergency reservoir through cavity 71 andpassage 37.

Upon making a gradual reduction in brake pipe pressure to effect aservice application of the brakes, the triple'valve piston 10 is movedto a service position, where the piston pressur engages the spring stop72 and in which the port 73 in the main slide valve 14 registers withpassage 69, said'portihaving been previously uncovered by thepreliminary move-l ment of the graduating valve 15. Fluid under pressureis then supplied to the brake cylinder 5 in the usual manner'to effect aservice application-of the brakes.

The gradual reduction in brake pipepressure on the emergency piston 17causes said piston to move into engagement with the spring stop 74, inwhich movement port 75 inthc graduating valve 22 registers with port 7 6in the slide valve 21. 7

Port 7 6 registers with apassage 7 7 leading to the atmosphere, througha restricted port 78, so that fluid under pressure is vented from thevalve chamber 18. and the quick action chamber 20, at the same rate asthe brake pipe pressure'is reduced. Thepiston 17is thus prevented frommoving to emergency position, when a gradual reduction in brake pipepressure isefl'ected. I Y

When the brake pipe pressure is suddenly reduced. toeffect an emergencyapplication of the brakes, .the triple valve piston 10 moves-toemergency position, in which position, the slide valve 14 uncoverspassage 43, so that fluid under pressure is supplied from the valvechamber 11 and the auxiliaryres- 1 ervoir 13,? to the brakecylinder,through a restricted port 44 in choke plug 45. The brake cylinder isthus directly supplied with fluid under pressure at a slow rate from theauxiliary reservoir, during an emergency application of the brakes.

Upon a sudden reduction in brake pipe pressure, the emergency piston 17moves out to emergency position, overcoming the resistance of the springstop 74, and slide valve 21 is shifted to a position in which cavity 79in the slide valve 21 connects passage 25 with exhaust passage 77.Cavity 71 in the slide valve 21 connects passage 41 with passage 80which is connected to chamber .30, through an annular recess 81, havinga plurality of openings 82, leading to said chamber. Fluid underpressurefrom the emergency reservoir 38 is thus supplied to chamber 30 at arapid rate, and flows to the brake cylinder 5, through passages 31 and32.

As above described, fluid under pressure initially, in an emergencyapplication, flows directly from the auxiliary reservoir at a slow rate,and from the emergency reservoir 38 at a rapid rate. The brake cylinderpressure builds up in chamber 30 and also in the chamber below thepiston valve 29, which chamber is connected to passage 80, through abypass 47. Vfhen the brake cylinder pressure acting in chamber 30 on theexposed area of the valve piston 23, has been increased to apredetermined degree, sufficient to overcome the pressure of spring 27,the valve piston 23 will be shifted from its lower seat. The full areaof the valve piston being now exposed to brake cylinder pressure, thevalve piston 23 will be quickly shifted to its upper seat.

In this position, the piston valve 29 cuts off communication frompassage 80 to chamber 30, so that further supply of fluid under pressurefrom the emergency reservoir 38 to the brake cylinder is prevented, andfluid under pressure is now supplied to the brake cylinder only at arestricted rate from the auxiliary reservoir.

In the. emergency position of the slide valve 21, a through portregisters with passage .37, so that chamber 36, below the valve piston 4is connected to valve chamber 18.. Thevalve chamber 18 and the quickaction chamber 20 are connected, through a port 86 in slide valve 21with a passage 87, having communication with the atmosphere, through arestricted port 88, so that fluid under pressure in the valve chamber18, the quick action chamber 20, and in chamber 36 is slowly vented tothe atmosphere at a rate determined by the restrictedport 88.

The inner seated area at the upper face of valv 'piston 4 issubject tobrake cylinder ton and when the fluid pressure below the supplying fluidunder pressure from said ad ditional source to the brake cylinder, saidadditional valve device being operated upon a I valvepistonhas beenreduced to a predetermined degree and the brake cylinder pressure hasbeen increased to apredetermined degree, the fluid pressures acting onthe upper face of the valve piston will overcome the reduced fluidpressure? acting in chamber' 36 and the pressure of spring 35, and thevalve piston willbe shifted downwardly, sothat communication is openedfrom the emergency reservoir to the brake cylinder, such i that a rapidflow, of fluidlunder pressure to the brake cylinder" is effected.

It will now be seen that in effecting an emergency applicationof thebrakes, a quick inshot of fluid under pressure is initially suppliedfrom the emergenc reservoir to the brake cylinder, while flui underpressure is flowing at a restricted rate from the auxiliary reservoir tothe brakecylinder, the pressure of fluid supplied being suflicienttoimove the brake cylinder piston (not shown) out and cause the brakeshoes (not shown) to en- I gage the wheels. 7 V

Theflow of fluid under pressure from the flows from the auxiliaryreservoir to the brake cylinderat a restricted rate and for a begradually applied throughout the train, but not with shocks.

Finally, after the brake cylinder pressure .has been graduallybuilt uptoa predetermineddegree, a final inshot of fluid under pressure issuppliedfrom the emergency reservoir tothe brake cylinder, in orderto apply thebrakeswith theforce desired in an t emergency application of the brakes.

i "by Letters Patent, is:

1. In a fluid pressure brake, the combinat1on with a brake pipe,auxiliary reservo1r,

brake cylinder, and an additional source of fluid under pressure, ofaservice valve device operatedupon agradualireduction in brakepipepressure forsupplying fluid under presi sure from theauxiliarylreservoir to the brake Y i cylinder, and upon a suddenreduction in brake pipe pressure forsupplying fluid under pressure fromthe auxiliary reservoir to the brake cylinder at a restricted. rate andadditional unitary valve device operated upon a sudden reduction inbrake plpe pressure for predetermined increase in brake cylinderemergency reservoir to the brake cylinder is I then cut off, so thatfluid under pressure only time interval sufficient to permit the brakesto such force as to cause severe,

is claimed asnew and desired tobesecured from the additional source tothe brake cylinder.

2; In a fluid pressure brake, the combination with a brake pipe,auiliar-y reservoir, brake cylinder, and an emergency reservoir normallycharged with fluid under pressure,

of a triple valve device operated upon a sud .den reduction in brakepipe pressure for directly supplying fluid under pressure from theauxiliary reservoir to the brake cylinder at a restricted rate and anadditional unitary valvedevice operated upon asudden reduction in brakepipe pressure for supplying, fluid under pressure from the emergencyreservoir to the brake cylinder, said additional valve device beingoperated upon a predetermined increase in brake cylinder pressure forcutting off the supply of fluid from the emergency reservoir to thebrake cylinder.

3; In a fluid pressure brake, the combination with a brake pipe,auxiliary reservoir, brake cylinder, and an emergency reservoir normallycharged with fluid underpressure, of a triple valve device operated upona suddenreduction in brake pipe pressure for di-v "=5 rectly supplyingfluid under pressure from the auxiliary reservoir to the brake cylinderat a restricted rate, anadditional unitary valve device operative toopen'communica- 7 tion for supplying fluid under pressure from theemergencyreservoir to the brake cylinder and operative upon apredetermined in} crease in brake cylinder pressure fer cutting off saidcommunlcation, and an emegency valve device operated upon a suddenreduction 1n brake plpe pressure for initiating the operation of sa1daddltional valve devlceb 4. In a fluid pressure brake, the combinabrakecylinder, and an additional source of fluld underpressure, ofa servicevalve detion with a brake pipe, auxiliary reservoir, V V

vice operated upona gradual reduction in brake pipe pressure forsupplying fluid under pressure from the auxiliary reservoir to the brakecylinder, and upon a sudden reduction in brake pipe pressure forsupplying fluid under pressure from the auxiliary reservoir to the brakecylinder at a restricted rate and an additional unitary valve deviceoperated upon a sudden reduction inbrake pipe pressure for supplyingfluid under pressure from said additional sourceto the brake cylinder,

said additional valve device being operated upon a predetermlnedincrease in brake cylinder pressurefor entirely cutting ofi the'sup Iiply of fluid from the additional source to the brake cylinder. I

Intestimony whereof, I have hereunto set my hand.

MABLE M. THOMAS,

Emeowtrz'ae 0f the Last Will and Testament 07 Thomas H. Thomas,deceased.

e pressure torcutting off the supply of fluid

